%% You should probably cite rfc8904 instead of this I-D.
@techreport{vesely-authmethod-dnswl-04,
    number =    {draft-vesely-authmethod-dnswl-04},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-vesely-authmethod-dnswl/04/},
    author =    {Alessandro Vesely},
    title =     {{DNSWL Email Authentication Method Extension}},
    pagetotal = 6,
    year =      2016,
    month =     apr,
    day =       4,
    abstract =  {This document describes an additional Email Authentication Method compliant with RFC 7601. The method consists in looking up the sender'IP in a DNS whitelist.},
}